Insecticide Innovations

Symptoms of Zimmerman pine moth typically show up in a thorough inspection—not so much in a casual drive-by.
Photos by John C. Fech, UNL.

New products and techniques for controlling pests on woody plants are always being introduced into the marketplace. As an arborist or tree service provider, it’s your job to stay abreast of all the changes, new ideas and innovations that are available. As with any new idea or method, “new” usually means change, which can mean making adjustments. Some people don’t like change; it means having to stop doing something that you are comfortable with and doing it differently, or stop doing it altogether. Others actually thrive on change and innovation; it invigorates them and is an impetus to strive for excellence in unique ways. As you read this article, think about whether you’re an embracer or resister of change, and how this influences how you view new products and techniques.

Why new?

The resisters can relate to this question: Why are we always looking for new products and techniques, and what’s wrong with the old stuff anyway? Actually, in terms of effectiveness, there’s nothing wrong with the old stuff … but, just like going from horses and bicycles to the automobile, the potential for something better is always out there. It’s what drives the free enterprise marketplace. In a capitalistic society like ours, if a pest control product can be made that is less expensive, easier to apply or is more effective, some company will develop and market the innovation. They make money and benefit along with the end users.

In today’s market, consideration of environmental impacts is always an important contemplation. Preserving the quality of water, soil and air is a concern that we all share and reflects as the flip side of the “let’s make it bigger, better, faster and stronger no matter what” approach to product development. If an existing or new product or technique helps to achieve the goal of pest control but negatively affects the environment, then it’s back to the drawing board for a better solution.

New products

One newer product on the market is Grandevo, which is derived from a bacterial strain of Chromobacterium subtsugae. This insecticide has been formulated to control caterpillars and other insects that feed on broadleaf and coniferous trees and shrubs. Among the target pests are armyworms, bagworms, spruce budworms, oakworms, fall webworms, green-striped mapleworms, gypsy moths, leafrollers, mealybugs, pine tip moths, tent caterpillars, mimosa webworms, aphids, lace bugs, mites, thrips and whiteflies. Product evaluations conducted at the University of Nebraska – Lincoln indicate that Grandevo applied at the higher usage rates will also control certain white grub and billbug species in turfgrass.

Another relatively new insecticide, emamectin benzoate, is marketed under the product name of TREE-äge, and offers an additional option for emerald ash borer (EAB) control. Other products labeled for EAB control include acephate, bifenthrin, cyfluthrin, dicrotophos, dinotefuran, imidacloprid, and permethrin. Application of some formulations of acephate, dicrotophos and imidacloprid require drilling numerous holes in the trunk around the base of the tree. In addition to causing damage to the water and nutrient-conducting system of the tree, these wounds could become pathways for invasion of pathogens and other ash pests. TREE-äge is expected to provide two years of control at the high label rate.

Developing concerns

Products in the neonicotinoid class of chemistry are drawing lots of concern these days from scientists, environmentalists and practitioners alike. A recent study by Larson, Redmond and Potter at the University of Kentucky examined the use of broad-spectrum insecticides and premix products containing two or more active ingredients and their effects on several species of beneficial insects. They found that ground beetles that ingested clothianidin or the premix of clothianidin and bifenthrin suffered mortality as high as the target black cutworm species. In addition, reduced numbers of bumblebee workers, immatures and honey pots were observed when exposed to these active ingredients at high concentrations. A third product, chlorantraniliprole (Acelepryn), produced no apparent adverse effects on any of the beneficial species in their study. Similar concerns have been expressed by other researchers concerning the use of imidacloprid, especially at high rates and over multiple years.

What’s not new?

That which is not new, not changed, and should not change, is the approach to common sense arboriculture care, made up of many components. The hallmark of the unchanged is thorough “triage for trees,” or diagnosis. Determining the actual cause of the apparent decline or malady is crucial and foundational for proceeding to subsequent control measures. Causal agent determination is important for providing good advice to the client, which may or may not lead to eventual product selection, especially in light of the generally accepted tenet that approximately half of tree demise situations are due to actual biotic causes (insects, diseases, nematodes, etc.) and half due to abiotic causes such as soil compaction, non-conducive soil pH, herbicide damage, improper planting technique, poor placement on the property and mulching errors. Also not new or particularly innovative, but equally important is the integration of routine inspection as a part of an overall treatment program.

Regular monitoring for the invasion of insect pests and diseases is not only sound for the considerations of tree health; it also serves as a potential opportunity for future applications to control damaging invaders. Scouting in this manner becomes a treat-as-needed approach, rather than a prescriptive schedule, where certain trees are sprayed, drenched or injected according to the calendar instead of actual need.

A key part of the prescriptive approach is to regularly communicate the results from the inspection with the client. Customers tend to be more favorable about paying for tangible information rather than a simple: “I looked it over and it’s all good; nothing needs to be treated at this point.” Being attentive to the preferences of the client is also important, in that some would rather communicate via email, some through phone calls, and others with an actual conversation on-site. The second key part of the prescriptive approach is charging a fee based on the extent of the inspection. ISA certified arborists invest considerable time and effort in becoming trained and experienced; this level of knowledge has considerable value and should be paid for accordingly.

Where are we headed?

The future direction of insecticide innovations, including improved formulations, efficacy and application techniques, are difficult to predict. However, their adoption will be affected by the risk takers in the marketplace and the bold theorists who strive to think outside the box. Although it’s difficult to predict, the factors influencing adoption will likely include a product or technique that is cost-effective and controls pests, and consumers and regulators demanding environmental safety standards. These factors will likely guide future product developments.